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CPU Profiling

If you built Ceph from source and compiled Ceph for use with oprofile you can profile Ceph’s CPU usage. See Installing Oprofile for details.

Initializing oprofile

oprofile must be initalized the first time it is used. Locate the vmlinux image that corresponds to the kernel you are running:

ls /boot
sudo opcontrol --init
sudo opcontrol --setup --vmlinux={path-to-image} --separate=library --callgraph=6

Starting oprofile

Run the following command to start oprofile:

opcontrol --start

Stopping oprofile

Run the following command to stop oprofile:

opcontrol --stop

Retrieving oprofile Results

Run the following command to retrieve the top cmon results:

opreport -gal ./cmon | less

Run the following command to retrieve the top cmon results, with call graphs attached:

opreport -cal ./cmon | less

Important

After you have reviewed the results, reset oprofile before running it again. The act of resetting oprofile removes data from the session directory.

Resetting oprofile

Run the following command to reset oprofile:

sudo opcontrol --reset

Important

Reset oprofile after analyzing data. This ensures that results from prior tests do not get mixed in with the results of the current test.